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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Análise da influência da geometria da matriz e do tempo de encharque no fechamento de defeitos internos de chapas do aço W.NR. 1.2714 / Influence of die geometry and holding time at temperature in the internal voids closing for forged w.nr. 1.2714 steel sheets

Queji, Licio Marcis January 2012 (has links)
No forjamento em matriz aberta o tempo gasto com retrabalhos e descarte de material não conforme gera custos e atraso no atendimento ao cliente. A fim de minimizar estas perdas, realizou-se uma revisão dos principais conceitos e fundamentos do processo de forjamento a quente em matriz aberta que influenciam na qualidade interna do produto. Com o intuito de desenvolver o processo de forjamento a quente em matriz aberta de chapas do aço W.NR. 1.2714 com espessura de 311 mm, largura de 634 mm e comprimento de 6000 mm, avaliou-se as descontinuidades internas deste produto. Através de análises preliminares realizadas, foi possível observar que a descontinuidade interna típica tratava-se de vazio. Com este resultado, desenhou-se um projeto experimental com corpos de prova quadrados com defeitos falsos de 30 mm de diâmetro e forjados para simular uma das etapas do forjamento de chapas. Foram selecionadas três combinações de matrizes e dois tempos de encharque. Todos os corpos de prova foram aquecidos no mesmo forno sob mesmas condições e forjados com duas reduções de 50 mm cada (33% - deformação relativa total), com giro de 180 graus entre elas. Após o resfriamento ao ar, as amostras sofreram alívio de tensões e foram cortadas em serra a 150 mm da extremidade do furo. As variáveis respostas do plano experimental foram a área do furo, o alargamento e o alongamento. A amostra forjada com a combinação de matriz AC, composta pela matriz funil na parte superior e mesa de forjamento na parte inferior e tempo de encharque de 7h teve o furo caldeado. Com todas as combinações de matrizes, o tempo de encharque de 7h levou a menor área do furo, maior alargamento e maior alongamento que o tempo de 11h. / In open die forging the time spent on rework, and disposal of non-compliant material, generates costs and delays in customer service. To minimize these losses, a review of key concepts and fundamentals of the process of open die forging was carried out emphasizing the internal quality of the product. In order to develop the process of open die hot forging in plate steel W.NR 1.2714 with a thickness of 311 mm, width 634 mm and a length of 6000 mm, internal discontinuities of this product were evaluated. Through preliminary analysis was possible to observe that the typical internal discontinuity were voids. With this result, experiments were designed for square specimens with false defects of 30 mm in diameter, which were forged in order to simulate one of the steps in the forging of plates. Three combinations of dies and two soak times were selected. All samples were heated in the same furnace on the same conditions and forged with two reductions of 50 mm each (33% - total relative deformation) with 180 degrees among them. After air cooling, the samples were heated up to promote a stress relief and were cut at a position 150 mm from the edge of the hole. Output variables were the area of the hole, widening and lengthening. The sample forged with the combination of die AC, with funnel die at the top and forging table at the bottom and the soaking time of 7 hours had the hole closed. For all combinations of dies, the soaking time of 7 hours led to a lower area of the hole, higher widening and lengthening than for 11hours soak time.
12

Aplicação da Teoria Elementar da Plasticidade e da simulação numérica para Forjamento em Matriz Aberta de eixo vazado

Correa, Fabio Junkes January 2014 (has links)
Este trabalho tem como propósito analisar o modelo matemático baseado na Teoria Elementar da Plasticidade (TEP) para o Forjamento em Matriz Aberta (FMA) de tarugos cilíndricos com o intuito de obter um eixo vazado para a utilização em aerogeradores. Foram realizadas simulações computacionais pelo Método dos Elementos Finitos (FEM) com efeito de comparação, utilizando o software Simufact.Forming 11.0. Foi exposto a sequência de cálculos e as interações realizadas para a construção de um modelo matemático a partir da TEP. Esse modelo matemático foi aplicado para os dois primeiros recalques em um tarugo cilíndrico vazado. Ambos os recalques foram executados no processo de Forjamento em Matriz Aberta. Tanto com o procedimento matemático baseado na TEP, quanto na simulação numérica baseado no FEM, foram obtidos os valores de distribuição de deformações, de distribuição de tensões e de forças de compressão requeridos pela prensa de forjamento para ambos os recalques. Com a conclusão dos experimentos físicos foi constatado que os valores das forças obtidos pela Teoria Elementar da Plasticidade (TEP) e pelo Método dos Elementos Finitos (FEM) variaram aproximadamente entre 5 a 15% em relação aos valores experimentais, possibilitando fazer comparações com variações e alterações na metodologia do processo. Observou-se que as regiões que apresentaram maiores concentrações de deformações equivalentes e tensões na direção z pelo modelo matemático (TEP) coincidiram com as regiões de maiores concentrações encontradas no software de simulação numérica (FEM). Desta forma, estima-se para a geometria estudada que a TEP pode ser empregada como uma ferramenta de simulação eficiente no processo de Forjamento em Matriz Aberta. / This paper aims to analyze the mathematical model based on the Plasticity Elementary Theory (TEP) for the Open Die Forging of cylindrical billets in order to get a hollow shaft for using in wind generator. Computer simulations were performed by the Finite Element Method (FEM) with purpose of comparison, using the software Simufact.Forming 11.0. It was exposed the calculations sequence and performed interactions to make a mathematical model from the TEP. This mathematical model was applied for the first two upsetting in a hollow cylindrical billet. Both upsetting were executed in the process of Open Die Forging. Both the mathematical method based in the TEP as the numerical simulation based in the FEM, it were obtained the value of the strains distribution, the stresses distribution and the compressive force required by the forging press for both upsetting. With the physical experiments concluded, it was found that the forces values obtained by the TEP and by the FEM ranged approximately between 5 and 15% compared to the experimental values, allowing make comparisons with variations and changes in the process methodology. It was observed that regions where showed higher concentrations of equivalent strains and stresses in the z direction by the mathematical model (TEP) coincided with the regions of higher concentrations found numerical simulation software (FEM). It’s demonstrated for the geometry studied that the TEP can be employed as a simulation efficient tool in the process of Open Die Forging.
13

Aplicação da Teoria Elementar da Plasticidade e da simulação numérica para Forjamento em Matriz Aberta de eixo vazado

Correa, Fabio Junkes January 2014 (has links)
Este trabalho tem como propósito analisar o modelo matemático baseado na Teoria Elementar da Plasticidade (TEP) para o Forjamento em Matriz Aberta (FMA) de tarugos cilíndricos com o intuito de obter um eixo vazado para a utilização em aerogeradores. Foram realizadas simulações computacionais pelo Método dos Elementos Finitos (FEM) com efeito de comparação, utilizando o software Simufact.Forming 11.0. Foi exposto a sequência de cálculos e as interações realizadas para a construção de um modelo matemático a partir da TEP. Esse modelo matemático foi aplicado para os dois primeiros recalques em um tarugo cilíndrico vazado. Ambos os recalques foram executados no processo de Forjamento em Matriz Aberta. Tanto com o procedimento matemático baseado na TEP, quanto na simulação numérica baseado no FEM, foram obtidos os valores de distribuição de deformações, de distribuição de tensões e de forças de compressão requeridos pela prensa de forjamento para ambos os recalques. Com a conclusão dos experimentos físicos foi constatado que os valores das forças obtidos pela Teoria Elementar da Plasticidade (TEP) e pelo Método dos Elementos Finitos (FEM) variaram aproximadamente entre 5 a 15% em relação aos valores experimentais, possibilitando fazer comparações com variações e alterações na metodologia do processo. Observou-se que as regiões que apresentaram maiores concentrações de deformações equivalentes e tensões na direção z pelo modelo matemático (TEP) coincidiram com as regiões de maiores concentrações encontradas no software de simulação numérica (FEM). Desta forma, estima-se para a geometria estudada que a TEP pode ser empregada como uma ferramenta de simulação eficiente no processo de Forjamento em Matriz Aberta. / This paper aims to analyze the mathematical model based on the Plasticity Elementary Theory (TEP) for the Open Die Forging of cylindrical billets in order to get a hollow shaft for using in wind generator. Computer simulations were performed by the Finite Element Method (FEM) with purpose of comparison, using the software Simufact.Forming 11.0. It was exposed the calculations sequence and performed interactions to make a mathematical model from the TEP. This mathematical model was applied for the first two upsetting in a hollow cylindrical billet. Both upsetting were executed in the process of Open Die Forging. Both the mathematical method based in the TEP as the numerical simulation based in the FEM, it were obtained the value of the strains distribution, the stresses distribution and the compressive force required by the forging press for both upsetting. With the physical experiments concluded, it was found that the forces values obtained by the TEP and by the FEM ranged approximately between 5 and 15% compared to the experimental values, allowing make comparisons with variations and changes in the process methodology. It was observed that regions where showed higher concentrations of equivalent strains and stresses in the z direction by the mathematical model (TEP) coincided with the regions of higher concentrations found numerical simulation software (FEM). It’s demonstrated for the geometry studied that the TEP can be employed as a simulation efficient tool in the process of Open Die Forging.
14

Analýza tečení materiálu při kování vačky / Analysis of Material Flow During Cam Forging

Kopečný, Adam January 2020 (has links)
The diploma thesis deals with the optimization of final position of overlaps on a forged cam. This part is manufactured in Šroubárna Kyjov, spol. s r.o. The cam is made from ČSN 14 109 (100Cr6) steel. The thesis is focused on the optimization of overlaps arising due to pressed burrs on the edges of the semifinished forging. Currently, the final position of these overlaps is very close to the edge of the pre-forged hole of the cam. Undesired chipping of material occurs during machining of the hole to the exact dimension. The final position of the overlaps is optimized by using the numerical simulation in Simufact Forming 15.0, including a verification simulation for optimal parameter settings. Various diameters of semifinished products, turned tools, and modification of shapes of the tools are tested in the thesis to prevent occurrence of the overlaps in undesired positions.
15

Výroba těla granátu / Producing of artillery shell

Moravec, Zdeněk January 2021 (has links)
The diploma thesis deals with the technology of production of the body of an artillery shell caliber 155 mm from C60 steel. The part is manufactured in series of 100,000 pieces. Based on a literature study and materials, a technological procedure of drop forging was designed, taking into account the specific shape of the forging. The volume of the starting blank and the forming force were determined. A suitable forming machine was selected based on the magnitude of the forming force. The design of tools for punching operations and reduction diameters of sets of rollers for forging stretching was also performed. In the technical and economic evaluation, the material costs for the production of the entire series were quantified.
16

Výroba opěry objemovým tvářením / Production of support by solid forming

Pfeifer, František January 2009 (has links)
PFEIFER František: Production of support by solid forming. A Graduation Thesis of Master´s Studies, the 5th Year of Study, the School-year 2008/2009, FSI VUT Brno, Department of Machining, May 2009, Pages No. 94, Pictures No. 37, Tables No. 3, Appendixes No. 13. The Graduation Thesis, elaborated in the framework of engineering studies, presents the production technology of support component from steel ČSN 12 010. A material is a rod of the 130 – 251 ČSN 42 5510. A yearly production is 95 000 pieces. Based on the studies of possible production technologies was proposed the technology of production by the vertical forging press LMZ 6500B (Šmeral Brno a. s.) with a nominal forming power of 65 MN, flash and pellicle trimming on a trimming press with a nominal power of 8 MN. For this option, the required technological calculations, the design of the die, the specification of production machines and a simulation forming process which is made in the software QFORM have been carried out.
17

Výroba držáku objemovým tvářením / Production of holder by solid forming

Nejedlý, Petr January 2010 (has links)
The project elaborated in frame of engineering studies branch 2307. The project is submitting design of technology production of holder by solid forming of steel 12 020.0. Pursuant to of the literary pursuit a problem of die forging and calculation was designed forging on a vertical cranked press LMZ 1600 and with nominal forging force 16MN (producer ŠMERAL Brno). The lower ejector is using for extrusion component.Heating billet is accomplished by using induction furnance type SOP 400kW.For trimming is used trimmning press LKOA 200 with force 2 MN. For holding of dies is used holder QLZK 1600/UC, dies are made of instrumental steel 19 552.9. A part of this project is economic estimation of production and produce of manufacturing drawings.
18

Výroba výkovku držáku rejdového čepu / Forging production of Holder of steering pivot

Moudrý, Michal January 2011 (has links)
MOUDRÝ Michal: Forging production of holder of steering pivot The project was elaborated in frame of engineering studies branch 2307. The aim of the project was to propose design of technology production of steering pivot holder using solid forming of steel 12 040.0. Based on literary study on die forging and made calculations forging on a vertical crank press LMZ 1000 with nominal forging force of 10MN was designed (producer ŠMERAL Brno). Lower and upper ejectors are used for ejection of components. Induction furnace type SOP 250/6-A30 P/L/T will be used for heating of the raw material. Trimming will be performed using trimming press LDO 315 A/S with press force of 3,15 MN. Dies are made of instrumental steel 19 663.9, for their clamping die clamping device QLZK 1000/UC will be used. A part of this project is economic evaluation of the production and development of production drawings. Keywords: solid forming, die forging, steel forging, holder
19

Adaptive Stichplanung im Freiformschmieden

Rechenberg, Roy, Pulawski, Michal, Zapf, Mathias, Korpala, Grzegorz, Prahl, Ulrich 28 November 2023 (has links)
Das Freiformschmieden ist eines der ältesten Umformverfahren in der Geschichte, das kontinuierlich durch technische Innovationen weiterentwickelt wurde. Die rasante Entwicklung in den Bereichen der Mess- und Regelungstechnik sowie der Rechenkapazität von IT-Systemen in den letzten Jahrzehnten bietet die Möglichkeit, das Freiform-schmieden auf seine nächste Entwicklungsebene zu heben. Um einen vollautonomen Schmiedeprozess zu etablieren, wird am Institut für Metallformung der TU Bergakademie Freiberg eine Schmiedezelle eingerichtet. Diese Verfügt über zwei Schmiedepressen, einen Ofen und einen Roboterarm vom Typ KR 360 L280-2 der Firma KUKA mit einer Traglast von bis zu 280 kg als Manipulator. Mithilfe eines 3D-Scansystems ist es möglich die Werkstückgeometrie zwischen einzelnen Stichen oder gar Pressenhüben zu erfassen. Weiterhin verfügt das Scansystem über drei Wärmebildkameras, welche während eines Scans die Oberflächentemperatur erfassen. Die einzelnen Komponenten der Schmiedezelle werden über einen Zentralrechner gesteuert.
20

Adaptive calculation of pass sequences for open die forging

Rechenberg, Roy, Pulawski, Michal, Zapf, Mathias, Korpala, Grzegorz, Prahl, Ulrich 28 November 2023 (has links)
Open-die forging is one of the oldest forming processes in history, which has been continuously developed through technical innovations. The rapid development in the fields of measurement and control technology and the computing capacity of IT systems in recent decades offer the opportunity to take open-die forging to a higher level. In order to establish a fully autonomous forging process, a forging cell is being set up at the Institute of Metal Forming at TU Bergakademie Freiberg. It consists of two forging presses, a furnace and a KR 360 L280-2 robot arm from KUKA as a manipulator with a load capacity of up to 280 kg. A 3D scanning system allows to capture the workpiece geometry between individual pass sequences or even single press strokes. Additionally, the scanning system is equipped with three thermal imaging cameras, which record the surface temperature during a scan. A central computer controls all individual components of the forging cell.

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